Profiled Blade and Fan Impeller

ABSTRACT

A profiled blade for a fan impeller comprising a profiled body produced from at least one bent sheet metal strip. The profiled body includes a profile top part with a convex curvature, a profile bottom part located at a distance from the profile top part, and first and second profile noses. Each of the profile noses has a convex curvature and joins the profile top part to the profile bottom part at ends of the profiled body. The profile top part and/or the profile bottom part is divided into at least first and second profile sections. The first profile section is joined to the first profile nose and the second profile section is joined to the second profile nose. A first free end region of the first profile section is joined to a second free end region of the second profile section by adhesive force.

CROSS REFERENCE TO RELATED APPLICATIONS

This application claims foreign priority under 35 U.S.C. §119(a)-(d) toApplication No. EP 16166124.4 filed on Apr. 20, 2016, the entirecontents of which are hereby incorporated by reference.

TECHNICAL FIELD

The disclosure relates to a profiled blade for a fan impeller,comprising a profiled body produced from at least one bent sheet metalstrip. The disclosure further relates to a fan impeller provided withsuch a profiled blade.

BACKGROUND

According to prior art known to the applicant but not published inprint, profiled blades for fan impellers are produced in acost-effective way by bending an oblong sheet metal strip transverselyto a longest edge. In this bending process, opposing first and secondend region edges of the sheet metal strip are brought close to oneanother. For this bending process, it is possible, for example, to use abending device with the aid of which a profile nose is created in thebending region. In the course of the bending process, a U-shapedprofiling is temporarily created, which becomes a drop-shaped profilingby continuing the bending process. This drop-shaped profiling representsthe final state of the bending process. In a subsequent machining step,an adhesive and/or positive joint between adjacent end region edges ofthe sheet metal strip can then be provided in order to produce a stableprofiled blade. By way of example, it is provided that the adjacent endregion edges of the sheet metal strip are wended and/or bonded and/orclinched (beaded) to one another.

SUMMARY

The disclosure is based on the problem of providing a profiled blade anda fan impeller with such profiled blades with an improved rigidity forthe profiled blades.

According to a first aspect of the disclosure, this problem is solvedwith a profiled blade comprising a profiled body produced from at leastone sheet metal strip and comprises a profile top part with a convexcurvature, a profile bottom part located at a distance from the profiletop part and a first and a second profile nose, wherein each of theprofile noses has a convex curvature and joins the profile top part tothe profile bottom part at the ends, wherein the profile top part and/orthe profile bottom part are/is divided into at least two profilesections, wherein a first profile section is joined to the first profilenose and wherein a second profile section is joined to the secondprofile nose, and wherein a first free end region of the first profilesection is joined to a second free end region of the second profilesection by adhesive force/adhesive bond.

In such a profiled blade, the at least one joint zone, which is, in adesign of the profiled blade from one or more sheet metal strips,necessary for joining end regions of the sheet metal strip(s), can berelocated from the zones of the profiled blade which are highly loadedby the occurring forces to less highly loaded zones. As a result, it ispossible to provide profiled blades which, in addition to anaerodynamically favorable profiling, ensure a reliable productionprocess and a high fatigue strength, in particular with differentprofiling for a pressure side and a suction side of the profiled blade.

While the profile top part is always convex, the profile bottom part canbe straight or convex or concave depending on application. In this, ithas to be assumed that the profiling of the profiled body is alwaysdesigned as a closed ring, preferably with a consistent curvature. As aresult of the angling of the at least one end region and the placementof the angled section of this end region between the profile top partand the profile bottom part, an advantageous joint zone can be createdfor joining the profile sections by adhesive force. Possible methods forjoining the profile sections by adhesive force/adhesive bond includewelding, soldering or bonding methods in particular.

It is advantageous if a free end region of at least one profile sectionis angled relative to the profile top part and the profile bottom partand located between the profile top part and the profile bottom part.This increases a contact area between the two end regions of the profilesections, ensuring improved strength for joining the end regions byadhesive force.

It is expedient if a free end region of a profile section is in planarcontact with a contact surface of another profile section which isstrip-shaped and offset against a surface of the profiled body. If asoldering or bonding method is used, the contact surface forms at theangled section a soldering or bonding gap with a large contact surfacebetween the two profile sections and thereby creates a mechanical jointwith a high load-bearing capacity.

It is preferred if the contact surface is oriented parallel to thesurface of the profiled body. In this way, a homogenous (welding orsoldering or bonding) gap is formed between the two profiled sections,which, in particular if a welding or bonding method is used, isadvantageous for a reliable mechanical coupling between the two profilesections. If a spot-welding method is used, the end region of the endregion in contact with the contact surface and the section of the endregion which defines the contact surface serve as a doubling of thesheet metal material. It is preferably provided that the contact surfaceis curved in the same way as the associated surface of the profiled bodyin order to ensure as constant as possible a gap width both in thelongitudinal and in the transverse direction of the gap.

In an advantageous further development, it is provided that the angledfree end region of the at least one profile section joins the profiletop part to the profile bottom part. In this way, the angled free endregion adopts, in addition to creating an advantageous contact surfacefor the respective other profile section, the function of a reinforcingstrut which reinforces the profile top part against the profile bottompart, thereby stabilizing it against bending moments acting on theprofiled blade in particular. The angled free end region of the at leastone profile section is preferably designed such that it joins theprofile top part to the profile bottom part in a region of maximumdistance from the profile bottom part, whereby a particularlyadvantageous reinforcement effect can be obtained for the profiledblade. For joining the angled free end region of the profile section tothe profile top part or the profile bottom part located at a distance,the same adhesive joining method is preferably used as for joining thetwo profile sections. By way of example, it is provided that bothadhesive joints are created by welding, in particular spot-welding.Alternatively, another joining method can be used, which is possiblymatched to the joining method for the two profile sections. Purely byway of example, if a welding method is used for the two profilesections, a thermally curing bonding method can be used for the adhesivejoint between the angled free end region of the profile section and theopposite profile top part or profile bottom part. In this case, theadhesive used is activated by the heat introduced in the weldingprocess.

In a further development, it is provided that the profile bottom parthas a concave curvature and/or that the profile bottom part comprises atleast two profile sections. If the profile bottom part is designed witha concave curvature, a corresponding profiled blade has anaerodynamically favorable profiling if used in a fan impeller. If theprofile bottom part is in addition or alternatively designed with atleast two profile sections and such profiled blades are used in a fanimpeller, the joint zone between the two profile sections lies in aregion of the profiled blade which is subjected to low mechanical loads.Compared to joint zones arranged differently, the forces acting on thejoint zone are relatively low, so that a reliable joint can be obtainedbetween the two profile sections.

It is advantageous if at least one of the free end regions isadditionally joined by adhesive force to the profile bottom part, theprofile top part or a profile element.

It is preferably provided that the profiled body is formed fromprecisely one sheet metal strip. This reduces the number of joint zonesto a minimum, so that the production costs for the profiled blade canlikewise be held at a low level. It further ensures an advantageous flowof forces within the profiled blade, which is not affected by aplurality of joint zones, so that a material-saving and thereforeweight-saving design of the profiled blade can be obtained from thisviewpoint as well.

It is expedient if both profile sections of the profile top part or theprofile bottom part have a free end region which is angled relative tothe profile top part and the profile bottom part and which extendsbetween the profile top part and the profile bottom part. Both free endsections of the profile sections can therefore be used as reinforcingstruts against the opposite profile top part or profile bottom part,whereby a profiled blade with a geometry capable of bearing particularlyhigh loads can be obtained. By way of example, it can be provided thatboth end regions, starting at a parting line between the two profilesections where an adhesive joint of the two profile sections is created,in particular by welding, extend at an acute angle relative to oneanother towards the opposite profile top part or profile bottom part.Alternatively, it can be provided that a gap, in particular in themanner of a groove, which determines the course of the surfaces of theprofile top part or profile bottom part even after the establishment ofthe adhesive joint, is formed between the two angled end regions.

It is preferably provided that each of the angled free end regions ofthe profile sections has a strip-shaped contact surface offset against asurface of the profiled body and that a profile element joins adjacentcontact surfaces and determines the surface of the profiled body in someregions. The profile element therefore has the task of covering the inparticular groove-shaped gap between the angled end regions of theprofile sections, thereby ensuring a surface for the profile top partand/or the profile bottom part which is smooth to the greatest extent atleast. By way of example, it is provided that an envelope around aprofiled body has to the greatest extent a drop shape, in particularwith a consistent curvature. The profile element is preferably designedas a sheet metal strip and is placed on the contact surface flush withthe surfaces of the profile sections and joined to the profile sectionsby adhesive force.

According to a second aspect of the disclosure, a fan impeller comprisesa disc-shaped circular blank which is designed coaxial with an axis ofrotation and comprises a hub assembly as well as a ring arrangedcoaxially with the axis of rotation and at a distance from the circularblank and a plurality of profiled blades, each of them comprising aprofiled body produced from at least one bent sheet metal strip andwhich comprises a profile top part with a convex curvature, a profilebottom part located at a distance from the profile top part and a firstand a second profile nose, wherein each of the profile noses has aconvex curvature and joins the profile top part to the profile bottompart at the ends, wherein the profile top part and/or the profile bottompart are/is divided into at least two profile sections, wherein a firstprofile section is joined to the first profile nose and wherein a secondprofile section is joined to the second profile nose, and wherein afirst free end region of the first profile section is joined to a secondfree end region of the second profile section by adhesive force, whichblades are arranged with pre-settable angular spacing in an annularspatial volume around the axis of rotation and fixed with opposite axialend faces to the circular blank and the ring.

A profiled blade designed according to the first aspect of thedisclosure can be produced using a method comprising the followingsteps: the provision of a sheet metal strip to a forming device, theforming of the sheet metal strip to produce a profile top part with aconvex curvature, a profile bottom part placed at a distance from theprofile top part and a first and a second profile nose which join theprofile top part and the profile bottom part at the ends, so that twoprofile sections each are formed at the profile top part and/or theprofile bottom part, wherein a first profile section is joined to thefirst profile nose and a second profile section is joined to the secondprofile nose and wherein a free end region of at least one profilesection is angled relative to the profile top part and the profilebottom part and located between the profile top part and the profilebottom part, and the fixing by adhesive force of at least one section ofthe end region on an adjacent section of the profile top part and/or theprofile bottom part.

BRIEF DESCRIPTION OF THE DRAWINGS

Advantageous variants of the disclosure are shown on the drawing, ofwhich:

FIG. 1 is a perspective representation of a first embodiment of aprofiled blade, wherein an angled end region between a profile top partand a profile bottom part is designed as a reinforcing strut.

FIG. 2 is a perspective representation of a second embodiment of aprofiled blade, wherein the angled end regions of opposite profilesections enclose an acute angle relative to one another.

FIG. 3 is a perspective representation of a third embodiment of aprofiled blade, wherein opposite profile sections, each with angled endregions, are designed as reinforcing struts between a profile top partand a profile bottom part and joined to one another by a profileelement.

FIG. 4 is a perspective representation of the third embodiment of aprofiled blade without the profile element.

FIG. 5 is a perspective representation of a variant if the thirdembodiment, wherein the profile element is additionally designed as areinforcing strut.

FIG. 6 shows a fan impeller for use with profiled blades according toFIGS. 1 to 5 and 7 to 14.

FIG. 7 is a perspective representation of a fourth embodiment of aprofiled blade.

FIG. 8 is a perspective representation of a fifth embodiment of aprofiled blade.

FIG. 9 is a perspective representation of a sixth embodiment of aprofiled blade.

FIG. 10 is a perspective representation of a seventh embodiment of aprofiled blade.

FIG. 11 is a perspective representation of a eighth embodiment of aprofiled blade.

FIG. 12 is a perspective representation of a ninth embodiment of aprofiled blade.

FIG. 13 is a perspective representation of a tenth embodiment of aprofiled blade.

FIG. 14 is a perspective representation of an eleventh embodiment of aprofiled blade.

DETAILED DESCRIPTION

In the embodiments of profiled blades 1, 41, 81, 121, 161, 201, 241,281, 321, 361, 401 described in greater detail below, structures ofidentical function are identified by the same reference numbers,increased by 40 in each case. The respective structures are describedonly once in each case. Initially, there will be an explanation of theprofiled blade 1 shown in greater detail in FIG. 1, on the basis ofwhich the basic components of the further profiled blades 41, 81, 121,161, 201, 241, 281, 321, 361, 401 shown in FIGS. 2 to 5 and 10 to 14 arerevealed.

A profiled blade 1 shown in FIG. 1 is produced, purely by way ofexample, from a rectangular sheet metal strip 2. The sheet metal strip 2has two longest edges 3, 4, which, in the illustrated embodiment, definea drop-type or kidney-type profile of the profiled blade 1 designed as aprofiled body 7, and two end region edges 5, 6. In the illustratedembodiment, the longest edges 3, 4 are arranged as mutually parallelplanes oriented at right angles to planes in which the end region edges5, 6 are located. The sheet metal strip 2 may, for example, be a sectionof a strip material not shown in the drawing or cut out of a flat metalsheet, not shown in the drawing.

In the illustrated embodiment, it is provided that the sheet metal strip2 has been bent, at a distance from the respective end regions 5, 6which corresponds to approximately 25 percent of the respective overalllength of the two longest edges 3, 4, in opposite directions and a rightangles to the two longest edges 3, 4, using different bending radiiwhich are considerably larger than a material thickness of the sheetmetal strip 2. This forming process results in a profiled body 7 having,purely by way of example, a constant profiling along a profile axis 8.

The profiled body 7 of the profiled blade 1 shown in FIG. 1 comprises,purely by way of example, a profile top part 9 with a convex curvature,a profile bottom part 10 with a concave curvature and two convex profilenoses 11, 12, which, in the illustrated embodiment, join the profile toppart 9 to the profile bottom part 10 to form a single piece. A firstprofile nose 11 forms a front edge 16 of the profiled blade 1, while asecond profile nose 12 forms a rear edge 15 of the profiled blade 1.

In the profiled blade 1, it is, purely by way of example, provided thatthe profile top part 9 is formed from two profile sections 17, 18, afirst profile section 17 extending between the first end region edge 5and the first profile nose 11, while a second profile section 18 extendsbetween the second end region edge 6 and the second profile nose 12. Inthe illustrated embodiment, it is provided that a surface 19 of theprofile top part 9 is defined by a top side 20 of the first profilesection 17 and by a top side 21 of the second profile section 18, andthat an end region 22 of the first profile section 17, which can also bedescribed as a first end region 22, lies on the second profile section18 in a manner described in greater detail below. The end region 23 ofthe second profile section 18, which can also be described as a secondend region 23, extends from the top side 21 into an interior 14 of theprofiled blade 1 which, with the exception of open end faces, is boundedby the sheet metal strip 2. Starting from the top side 21 of the secondprofile section 18, the end region is provided with two at leastsubstantially rectangular and opposite folds 24, 25 in order to form astrip-shaped contact surface 26 offset against a surface 19 of theprofiled body 7 and preferably extending parallel to the surface 20 ofthe first profile section 17 and offset by the material thickness of thesheet metal strip 2. From the contact surface 26, the end region 23extends, after a further at least substantially rectangular fold 27, atright angles to a concave inner surface 28 of the profile bottom part 10and is at the end bent once more at right angles with a fold 31. Thisforms a contact surface 29, which is parallel to the inner surface 28and can be used for joining to the inner surface 28 by adhesive force.

By way of example, it is provided that the two profile sections 17, 18are welded to one another at the surface 19 in a manner not shown indetail in the region of a parting line 30. Following the welding of theparting line 30, it can further be provided that the contact surface 29is joined to the inner surface 28 by adhesive force using a liquidadhesive. Alternatively, the two profile sections 17, 18 can besoldered, exclusively welded or exclusively bonded to one another.

In the second embodiment of a profiled blade 41 shown in FIG. 2, the twoend regions 62, 63 of the profile sections 57, 58 are, starting from arespective top side 60, 61 defining the surface 59 of the profile toppart 49 of the profiled blade 41, bent at an acute angle towards therespective top side 60, 61. As a result, the two end regions 62, 63extend at an angle to the inner surface 68 of the profile bottom part 50in the interior 54 of the profiled blade 41. In addition, both endregions 62, 63 are provided with a fold 71, 72 near the end region edge45, 46, in order to form there in each case a contact surface 69, whichis oriented parallel to the inner surface 68 and can be joined to theinner surface 68 by adhesive force. In the region of each fold 64, 65,the opposite profile sections 57, 58 form a parting line 70, which canbe closed by welding, for example. In the process of this weldingoperation, an adhesive joint can be produced between the two profilesections 57, 58 as well.

In the third embodiment of a profiled blade 81 shown in FIGS. 3 and 4,both profile sections 97, 98 are designed like the second profilesection 18 of the profiled blade 1 shown in FIG. 1 and arranged at adistance from one another. Each of the end regions 102, 103 of theprofile sections 97, 98 therefore has a series of opposing folds 104,105, 107, 111. In contrast to the embodiment according to FIG. 1, adivision of the profile bottom part 90 into the two profile sections 97,98 is provided in the third embodiment of the profiled blade 81, so thatthe two end regions 102, 103, starting from the profile bottom part 90,extend to the profile top part 89 and are there fixed to an innersurface 113 of the profile top part 89 with contact surfaces 109. Eachof the end regions 102 has a strip-shaped contact surface 106, which isoriented parallel and with an offset to the respective top side 100, 101of the profile sections 97, 98 and has a distance from the respectivetop side 100, 101 which corresponds to a material thickness of the sheetmetal strip 82 in the illustrated embodiment. As a result of the spacingof the two end regions 102, 103, a gap 115 is formed between the twostrip-shaped contact surfaces 106 of the two end regions 102, 103. Thisgap 115 is undesirable in terms of aerodynamics and furthermore has anegative effect on the dimensional stability of the profiled blade 81.In order to avoid these negative effects, the gap 115 is covered by aprofile element 114, which is plate-shaped purely by way of example andjoined to the two contact surfaces 106 of the two end regions 102, 103by adhesive force. This measure creates a two-part profiled blade 81 ofhigh strength.

The profiled blade 121 shown in FIG. 5 is a variant of the profiledblade 81, differing only in the design of the profile element 154. Incontrast to the profile element 114 shown in FIG. 3, this is notplate-shaped with a slightly concave curvature, but rather has a centralweb 156, which is integrally formed, oriented parallel to the profileaxis 128, extends, starting from an underside 157 of the profile element154, towards the inner surface 151 of the profile top part 129 and isfixed to this inner surface 151 by adhesive force, thereby providing anadditional stabilization of the profiled blade 121.

By way of example, it can be provided that the profiled blades 1, 41,81, 121, 161, 201, 241, 281, 321, 361, 401 described above are used inthe production of a fan impeller 560 as shown, purely by way of example,in FIG. 6 equipped with profiled blades 1. Such a fan impeller 560 isused to deliver a gaseous fluid and, purely by way of example, comprisesa plurality of blades 1 arranged in an annular spatial volume about anaxis of rotation 92 with pre-settable angular spacing. With their axialopposing end regions, the blades 1 are fixed to supporting members 563,564. A first supporting member is designed as a disc-shaped circularblank 563 coaxial with the axis of rotation and comprises a hub assembly565. A second supporting member, on the other hand, is designed as aring 564 coaxial with the axis of rotation 562. In this context, it isprovided that each of the profiled blades 1 is arranged with the firstprofile nose 11 radially on the inside, while the second profile nose 12is arranged radially on the outside. The curvature of the profile toppart 9 and the profile bottom part 10 causes, at a rotation of the fanimpeller 560 about the axis of rotation 562 in a clockwise direction asshown in FIG. 6, a rearward directed rotation of the profiled blades 1,resulting in an axial inflow of fluid along the axis of rotation 562through the ring 564 into the annular spatial volume and from thereoutwards in the radial direction. The fluid first approaches the profilenose 11 of the profiled blade 1 and then flows towards the outside alongthe profiled blades 1 in the radial direction.

As a result of the design of the profiled blades 1 as profiled bodies 7,a very strong and cost-effective fan impeller 560 is obtained incombination with the disc-shaped circular blank 563 and the ring 564.

The profiled blades 161, 201, 241, 281, 321, 361, 401 and 441 shown inFIGS. 7 to 14 can be divided into two groups. The profiled blades 161,201, 241 form a first group, while the profiled blades 281, 321, 361,401, 441 form a second group.

In the profiled blades 161, 201, 241 of the first group, it is providedthat the profile top parts 169, 209, 249 and the profile bottom parts170, 210, 250 of the respective profiled bodies 167, 207, 247 aredivided into profile sections 177, 217, 257 and 178, 218, 258, and thatend regions 182, 222, 262 and 183, 223, 263 are arranged opposite oneanother with their end faces and joined to one another by adhesiveforce. To ensure a dimensional stability for the profiled blades 161,201, 241, a profile element 194, 234, 274 adhesively joined to facinginner surfaces of the end regions 182, 222, 262 and 183, 223, 263 is ineach case located between the end regions 182, 222, 262 and 183, 223,263. In the embodiment according to FIG. 7, the profile element 194 isS-shaped. In the embodiment according to FIG. 8, the profile element 234is designed in the manner of a double T-beam (i.e., an I-beam). In theembodiment according to FIG. 9, the profile element 274 is designed as avariant of the profile element 234 according to FIG. 8 and has onopposing surfaces an external web 275 each, by which the end regions262, 263 lying on the profile element 274 are spaced from one another.

The profiled blades 281, 321, 361, 401, 441 of the second group can bedescribed as variants or further developments of the profiled blades 1,41, 81, 121, wherein, as in the case of the profiled blades 161, 201,241 of the first group, both the profile top parts 289, 329, 369, 409,449 and the profile bottom parts 290, 330, 370, 410, 450 are dividedinto profile sections 297, 337, 377, 417, 457 and 298, 338, 378, 418,458. As in the case of the profiled blades 1, 41, 81, 121, at least oneof the end regions 302, 342, 382, 442, 462 and 303, 343, 383, 443, 463of the profiled blades 281, 321, 361, 401, 441 is profiled in such a waythat it can serve as a contact surface for an opposite end region each.

Accordingly, the profiled blade 281 according to FIG. 10 is a variant ofthe profiled blade 1 according to FIG. 1.

In the profiled blade 321, both end regions 343 of the profile top part329 and the profile bottom part 330 are folded twice in oppositedirections, thereby forming contact surfaces for the two end regions 342of the profile top part 329 and the profile bottom part 330.

In the profiled blade 361, the end region 382 of the profile section 377of the profile top part 369 rests against a contact surface of thefolded end region 383 of the profile section 378. Furthermore, the endregion 383 of the profile section 378 of the profile bottom part 370rests against a contact surface of the folded end region 377 of theprofile bottom part 370. Accordingly, the profiled blade 361 has tworeinforcing struts between the profile top part 369 and the profilebottom part 370.

In the profiled blades 401 and 441, the end regions 423 of the profiletop part 409 and the profile bottom part 410 form contact surfaces forthe end regions 422 of the profile top part 409 and the profile bottompart 410. The end regions 423 are in addition folded in such a way thatthe end region 423 of the profile top part 409 is arranged with its endface opposite the end region 423 of the profile bottom part 410, wherebya gap not identified in detail is formed, which can be joined byadhesive force before the end regions 422 of the profile top part 409and the profile bottom part 410 are joined to the contact surfaces byadhesive force.

The profiled blade 441 is a variant of the profiled blade 401, whereinthe end region 463 of the profile top part 409 forms a contact surfaceboth for the end regions 462 of the profile top part 449 and the profilebottom part 450 and for the end region 463 of the profile bottom part450. In this case, it can likewise be provided that end regions 463 ofthe profile top part 449 and the profile bottom part 450 are firstjoined together by adhesive force and that the end regions 462 are thenjoined to the contact surfaces of the end regions 463 by adhesive force.

What is claimed is:
 1. A profiled blade for a fan impeller, comprising:a profiled body produced from at least one bent sheet metal strip, theprofiled body comprising: a profile top part with a convex curvature; aprofile bottom part located at a distance from the profile top part; andfirst and second profile noses each having a convex curvature andjoining the profile top part to the profile bottom part at ends of theprofiled body, wherein at least one of the profile top part or theprofile bottom part is divided into at least first and second profilesections, wherein the first profile section is joined to the firstprofile nose and the second profile section is joined to the secondprofile nose, and wherein a first free end region of the first profilesection is joined to a second free end region of the second profilesection by adhesive force.
 2. The profiled blade according to claim 1,wherein a free end of at least one profile section is angled relative tothe profile top part and the profile bottom part and located between theprofile top part and the profile bottom part.
 3. The profiled bladeaccording to claim 1, wherein a free end region of a profile section isin planar contact with a contact surface of another profile section, thecontact surface being strip-shaped and offset against a surface of theprofiled body.
 4. The profiled blade according to claim 3, wherein thecontact surface is oriented parallel to the surface of the profiledbody.
 5. The profiled blade according to claim 1, wherein the angledfree end region of the at least one profile section joins the profiletop part to the profile bottom part.
 6. The profiled blade according toclaim 1, wherein the profile bottom part has a concave curvature and/orthe profile bottom part has at least two profile sections.
 7. Theprofiled blade according to claim 1, wherein at least one of the freeend regions is additionally joined by adhesive force to the profilebottom part or the profile top part or to a profile element.
 8. Theprofiled blade according to claim 1, wherein the profiled body is formedfrom precisely one sheet metal strip.
 9. The profiled blade according toclaim 1, wherein both the first and second profile sections of theprofile top part or the profile bottom part have a free end region,which is angled relative to the profile top part and the profile bottompart and which extends between the profile top part and the profilebottom part.
 10. The profiled blade according to claim 9, wherein eachof the angled free end regions of the profile sections has astrip-shaped contact surface which is offset against a surface of theprofiled body, and wherein a profile element joins adjacent contactsurfaces and in some regions defines the surface of the profiled body.11. A fan impeller, comprising: a disc-shaped circular blank arrangedcoaxially with an axis of rotation and comprising a hub assembly; a ringarranged coaxially with the axis of rotation and at a distance from thecircular blank; and a plurality of profiled blades fixed to the circularblank and to the ring with axially opposite end faces, each of theprofiled blades having a profiled body produced from at least one bentsheet metal strip, the profiled body comprising: a profile top part witha convex curvature; a profile bottom part located at a distance from theprofile top part; and first and second profile noses each having aconvex curvature and joining the profile top part to the profile bottompart at ends of the profiled body, wherein at least one of the profiletop part or the profile bottom part is divided into at least first andsecond profile sections, wherein the first profile section is joined tothe first profile nose and the second profile section is joined to thesecond profile nose, and wherein a first free end region of the firstprofile section is joined to a second free end region of the secondprofile section by adhesive force.